• 제목/요약/키워드: initial control

검색결과 4,100건 처리시간 0.035초

영구자석동기전동기의 부하추정을 통한 센서리스 전환 알고리즘 (Sensorless Transition Algorithm of PM Synchronous Motor by Load Torque Estimation)

  • 김동현;조관열;김학원
    • 전력전자학회논문지
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    • 제26권5호
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    • pp.349-356
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    • 2021
  • Permanent magnet synchronous motors are mainly used in the traction of electric vehicle and home application products including air-conditioners and refrigerators. For sensorless control without rotor position sensors, I-F control is applied for initial starting at low speeds, and mode is changed to sensorless control when the rotor speed is sufficiently accelerated for estimating rotor position. When the mode is changed to the sensorless control from the open-loop starting, the initial integral value of the speed controller should be considered by load condition; otherwise, the transition to sensorless control may fail. The sensorless transfer algorithm of PM synchronous motor based on load condition for smooth transition is proposed. The performance of the proposed sensorless transfer algorithm was verified by experiments.

암 환자의 발생 초기 의료비와 이에 영향을 미치는 요인 (Costs of Initial Cancer Care and its Affecting Factors)

  • 김소영;김성경;박종혁;박은철
    • Journal of Preventive Medicine and Public Health
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    • 제42권4호
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    • pp.243-250
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    • 2009
  • Objectives : The purposes of this study is to estimate the cost of cancer care after its diagnosis and to identify factors that can influence the cost of cancer care. Methods : The study subjects were patients with an initial diagnosis one of four selected tumors and had their first two-years of cancer care at a national cancer center. The data were obtained from medical records and patient surveys. We classified cancer care costs into medical and nonmedical costs, and each cost was analyzed for burden type, medical service, and cancer stage according to cancer types. Factors affecting cancer care costs for the initial phase included demographic variables, socioeconomic status and clinical variables. Results : Cancer care costs for the initial year following diagnosis were higher than the costs for the following successive year after diagnosis. Lung cancer (25,648,000 won) had higher costs than the other three cancer types. Of the total costs, patent burden was more than 50% and medical costs accounted for more than 60%. Inpatient costs accounted for more than 60% of the medical costs for stomach and liver cancer in the initial phase. Care for latestage cancer was more expensive than care for early-stage cancer. Nonmedical costs were estimated to be between 4,500,000 to 6,000,000 won with expenses for the caregiver being the highest. The factors affecting cancer care costs were treatment type and cancer stage. Conclusions : The cancer care costs after diagnosis are substantial and vary by cancer site, cancer stage and treatment type. It is useful for policy makers and researchers to identify tumor-specific medical and nonmedical costs. The effort to reduce cancer costs and early detection for cancer can reduce the burden to society and improve quality of life for the cancer patients.

포도 종류를 달리한 포도 약주의 발효 특성 (Fermentation Characteristics of Grape Yakju made with Three Kinds of Grape)

  • 이지연;곽은정
    • 동아시아식생활학회지
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    • 제19권1호
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    • pp.96-104
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    • 2009
  • Three kinds of grape yakju (Kyoho, Campbell and Moru) and grape-free control were fermented with rice using koji of Aspergillus kawachii as a fermenting agent, and their fermentation characteristics were investigated. For the three yakju, reducing sugar content decreased slowly over 2 days fermentation after an initial rapid decrease. In case of Brix, the reducing sugar content increased gradually after increasing rapidly during the first 2 days of fermentation. The Kyoho and Moru groups displayed a gradual increase in reducing sugar content after an initial 2-day decrease, and the sugar content of the Campbell group increased gradually during fermentation. Uniformly, pH increased gradually after an initial 2-day decrease, however total acid increased continuously throughout fermentation. Alcohol content of yakju showed almost no change after increasing until day 6 (Kyoho) of day 4 (others), with the control displaying the highest content. Control $\alpha$-amylase activity decreased gradually after an initial 2-day increase, while that of the three yakju decreased throughout fermentation. Activities of $\beta$-amylase activities paralleled the results of reducing sugar. Concerning total anthocyanin, the Moru and Campbell groups displayed a rapid increase until day 2, a decrease until day 12, and a gradual increase thereafter. While the Kyoho and control groups displayed virtually no change after an initial 2-day increase until day 12, after which a gradual increase also occurred. In concerning sensory evaluation, Moru yakju scored highest for violetness, flavor of grape, and sweet taste, and also displayed a low alcohol content. These attributed Moru yakju the preferred choice.

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Modular approach model에 의한 분리공정의 모사 (Modular approach model for separation process simulation)

  • 김경숙;조영상
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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    • pp.372-376
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    • 1989
  • One of the major difficulties with modular approach model of separation process simulation is initial guess problem. Only accurate initial guess make the problem converge and large computer memory and calculating time are required. In this study, we use the initial bottom guess value same as given feed condition and update the value the .theta.method. So we examine;(1)the problem converges using initial guess with large range, (2)computer memory and calculating time are reduced considerably.

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Development of the Real-time Initial Alignment Algorithm using the Kalman Filter

  • Oh, Sang-Heon;Hwang, Dong-Hwan;Lee, Sang-Jeong
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.61.2-61
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    • 2001
  • The purpose of the initial alignment of a SDINS is to get a coordinate transformation matrix from the body frame to the navigation frame. The initial alignment is one of the most important processes in the navigation system since its error has a large influence on the navigation solution. In this paper, a real-time initial alignment algorithm for the SDINS is developed using the Kalman filter. The steady state error analysis is performed for the developed Kalman filter technique and the gyrocompass loop method. The performance of the developed alignment method is compared with the gyrocompass loop method through the real-time alignment experiments.

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양질 조사료 급여에 따른 한우 송아지의 IgY 처리효과 (Effects of IgY Supplementation on Hanwoo Calves Fed withHigh Quality Roughage)

  • 홍병천;신종서;박병기;김병완;성경일;안준상
    • 한국초지조사료학회지
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    • 제36권2호
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    • pp.159-166
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    • 2016
  • This study was conducted to examine the effect of IgY supplementation on growth performance, blood metabolism, and disease occurrence in the weaned calves at 3 or 4 month of age. Average daily gain (ADG) and feed intakes were not affected by IgY supplementation, regardless of weaning months. White blood cell (WBC) count of the control group was higher in the final stage than in the initial stage (p<0.05), while that of the IgY supplemented group was lower in the final stage compared to the initial stage (p<0.05). regardless of treatments. Hematocrit (HCT) and red blood cell (RBC) counts were lower in the final stage than in the initial stage (p<0.05), but mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) counts were higher in the final stage than in the initial stage, regardless of treatments. In the control group, concentrations of albumin and globulin were higher in the final stage compared to the initial stage in the weaned calves at 3 month of age (p<0.05), and concentration of blood urea nitrogen (BUN) was increased in the IgY supplemented group. In the control group, concentrations of aspartate aminotransferase (AST) and gamma (${\gamma}$)-glutamyl transferase (GGT) were higher in the final stage compared to the initial stage (p<0.05). In contrast, concentrations of aspartate aminotransferase (AST) and gamma(${\gamma}$)-glutamyl transferase (GGT) were lower in the final stage compared to the initial stage for the IgY supplemented group. A diarrhea calf was only found in the control group. Manure score was higher in the control group compared to IgY supplemented group (p<0.05). Thus, these results indicates that IgY supplementation had positive effects on some blood metabolites, fecal condition score and diarrhea without negative effect on growth performance of the weaned Hanwoo calves.

자동조정기능의 지능형제어를 위한 신경회로망 응용 (Application of Neural Network for the Intelligent Control of Computer Aided Testing and Adjustment System)

  • 구영모;이승구;이영민;우광방
    • 전자공학회논문지B
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    • 제30B권1호
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    • pp.79-89
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    • 1993
  • This paper deals with a computer aided control of an adjustment process for the complete electronic devices by means of an application of artificial neural network and an implementation of neuro-controller for intelligent control. Multi-layer neural network model is employed as artificial neural network with the learning method of the error back propagation. Information initially available from real plant under control are the initial values of plant output, and the augmented plant input and its corresponding plant output at that time. For the intelligent control of adjustment process utilizing artificial neural network, the neural network emulator (NNE) and the neural network controller(NNC) are developed. The initial weights of each neural network are determined through off line learning for the given product and it is also employed to cope with environments of the another product by on line learning. Computer simulation, as well as the application to the real situation of proposed intelligent control system is investigated.

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Structure-Control Combined Optimal Design of 3-D Truss Structure Considering Intial State and Feedback Gain

  • Park, Jung-Hyen
    • 한국해양공학회지
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    • 제17권4호
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    • pp.66-72
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    • 2003
  • This paper proposes an optimum, problematic design for structural and control systems, taking a 3-D truss structure as an example. The structure is subjected to initial static loads and time-varying disturbances. The structure is controlled by a state feedback H$_{\infty}$ controller which suppress the effects of disturbances. The design variables are the cross sectional areas of truss members. The structural objective function is the structural weight. For the control objective, we consider two types of performance indices, The first function represents the effect of the initial loads. The second function is the norm of the feedback gain, These objective functions are in conflict with each other but are transformed into one control objective by the weighting method. The structural objectives is treated as the constraint, By introducing the second control objective which considers the magnitude of the feedback gain, we can create a design to model errors.

표적충돌각과 최대가속도 제한을 고려한 최적유도기법 (Optimal guidance with terminal impact angle and control constraint)

  • 류창경;조항주
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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    • pp.601-606
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    • 1992
  • In this paper, we consider an optimal guidance problem with both the terminal impact angle and control constraints in addition to the usual zero miss distance constraint. We first present the optimal solution of the problem for the missile of an arbitrary order, and show that it is a linear combination of a step response and a ramp response of the missile. Therefore the usual practice of using the control obtained by saturating the optimal solution for the case of unlimited control may result in a large terminal miss. A method called the initial command saturation is suggested to reduce this terminal miss, where the control in the initial phase of guidance is forced to be saturated until a certain condition for a guidance variable is met.

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산업용 로봇트의 정밀제어를 위한 학습제어 방법의 개발 (A Development of Learning Control Method for the Accurate Control of Industrial Robot)

  • 원광호;허경무
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.346-346
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    • 2000
  • We proposed a method of second-order iterative learning control with feedback, which shows an enhancement of convergence speed and robustness to the disturbances in our previous study. In this paper, we show that the proposed second-order iterative learning control algorithm with feedback is more effective and has better convergence performance than the algorithm without feedback in the case of the existence of initial condition errors. And the convergence woof of the proposed algorithm in the case of the existence of initial condition error is given in detail, and the effectiveness of the Proposed algorithm is shown by simulation results.

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